1. Field of the Invention
The present invention relates to a reservoir for supplementing the working fluid supplied to a hydraulic master cylinder for the brakes or the clutch of a vehicle, and in particular, a reservoir used for a tandem hydraulic master cylinder for two systems, and having a level detector contained in a fluid chamber, for detecting a reduction in the fluid level of the reservoir.
2. Description of the Related Art
Reservoirs disclosed in JP-A-63-202560U and JP-A-3-73257U, for example, are well-known parts provided for the hydraulic master cylinder that hydraulically actuates the brakes or the clutches of vehicles.
These reservoirs are employed for a tandem hydraulic master cylinder provided for two hydraulic systems. In the bottom wall of each of these reservoirs, there are formed a first union hole and a second union hole, which communicate with cylinder holes of the hydraulic master cylinder. The reservoir, in this case, is an integrally formed on the upper portion of the hydraulic master cylinder. And, the reservoir is located in an engine compartment that is separated from a passenger compartment by a dash panel.
A level detector is provided in a fluid chamber, which stores a working fluid inside of the reservoir. Such detector, in many cases, is constituted by a combination of a lead switch positioned at the bottom of the fluid chamber, and a float which is floated at the fluid level above the lead switch. Then, as the level of the working fluid is lowered and the float descends and approaches the lead switch, contact points on the lead switch are closed and an alarm unit or a warning signal light is activated, to thereby notify a driver that the volume of the working fluid in the fluid chamber has been reduced to a predetermined fluid level.
Recently, however, the arrangement of components has been complicated in a layout of the inside of the engine compartment. Further, an instrument panel and a windshield in the passenger compartment project upward in the vicinity of the dash panel whereat the hydraulic master cylinder and the reservoir can be mounted. Therefore, the locations whereat the hydraulic master cylinder and the reservoir can be mounted, and the shapes thereof are greatly limited.
Therefore, the reservoir positioned on the upper portion of the hydraulic master cylinder has a flattened shaped with a lowly limited height. In order to compensate for the reduced volume due to this shape, the length of the reservoir has been extended in the longitudinal direction of the vehicle body and a fluid injection port is formed in its upper front portion, shifted from the location from which the dashboard and the windshield of the vehicle are projected. As a result, even upon only a small behavior of a vehicle, the working fluid in the fluid chamber is waved in the fluid level, or the fluid may surge forward or backward. Therefore, a float on the fluid level reacts sensitively, whereby the lead switch of a level detector is erroneously activated, or union holes may be exposed on the fluid level.
As a countermeasure, it has been proposed that the fluid chamber be divided into multiple small chambers. With this arrangement, however, the vehicle body front chamber where the fluid injection port is opened communicates with neither the first nor the second union hole, and the working fluid stored in this chamber is not used.
Taking the above drawback into account, the object of the present invention is to provide a reservoir for a hydraulic master cylinder for a vehicle in which, even though the reservoir is extended in the longitudinal direction of the vehicle body because of the limited height, the working fluid in a fluid chamber can be utilized, and erroneous operations of the level detector and the exposure of union holes can be prevented as much as possible.
To achieve the objective, according to the present invention, there is provided a reservoir for a tandem-type hydraulic master cylinder of a vehicle, including:
a fluid injection port disposed on an upper portion at the front side of the reservoir;
a bottom wall defining a first union hole and a second union hole adapted to be communicated with cylinder holes formed in the tandem-type hydraulic master cylinder;
a level detector arranged in a fluid chamber inside the reservoir, the level detector having a lead switch and a float; and
first and second partition walls respectively extending along the widthwise direction of the reservoir within the fluid chamber so as to divide the fluid chamber into a first fluid chamber, a second fluid chamber and a third fluid chamber in this order from the front side of the reservoir,
wherein the fluid injection port communicates with the first fluid chamber, and the first partition wall at the front side of the reservoir that divides into the first fluid chamber and the second fluid chamber is positioned to the upper surface of the first union hole so that the first union hole is communicated with the first fluid chamber and the second fluid chamber,
wherein the second union hole and the level detector are arranged in one of either the second fluid chamber or the third fluid chamber, or an area extending over the second and the third fluid chambers; and
wherein an opening is formed in an upper portion of the second partition wall at the rear side of the reservoir that divides into the second and the third fluid chambers, so that the second and the third fluid chambers communicate with each other.
Here, the wordings xe2x80x9cthe widthwise direction of the reservoirxe2x80x9d mean a lateral direction of FIG. 2, and represent the substantially same direction as the widthwise direction of the vehicle in a state that the reservoir is arranged in the vehicle.